It could have been a day of triumph as Southeast Asia's leaders pledged a new era in human rights for their troubled region. Instead, their extensive efforts to defend a watered-down plan for a rights' body were scuppered when the premiers from Myanmar and Cambodia threatened to walk from a rare meeting with representatives of the region's civil groups and activists.

The refusal by Myanmar Prime Minister Thein Sein and his Cambodian counterpart Hun Sen to meet representatives from their own countries sparked a classic Asean-style compromise - they got their way and host, Thai Prime Minister Abhisit Vejjajiva, met activists from the two countries outside the meeting.

All 10 Asean leaders attended, hearing pleas for wider engagement with community groups and activists, irrespective of political differences. Thein Sein and Hun Sen sat in glowering silence throughout, said one source inside the meeting.

For some veteran envoys from the Association of Southeast Asian Nations and many activists, the situation highlighted their worst fears that the grouping's more hardline member countries were able to hijack a well-intentioned effort that had been years in the making.

Despite an early push from some more liberal members to create a body with investigative and enforcement abilities, a draft plan confirmed by Southeast Asian foreign ministers this weekend offers no such teeth. In its place are repeated references to Asean's political and cultural diversity and its long-cherished policy of not interfering in the internal affairs of member countries.

'It really highlights what we are all up against,' said Myanmar activist Khin Ohmar, who found herself shut out of the session despite being carefully selected by Asean officials.

'Despite its best intentions, Asean will not to be able to change so long as Burma's generals remain in power ... They hide behind non-interference and can drag the whole thing down to their level,' said Ms Ohmar, a co-ordinator of the Forum for Democracy in Burma.

In her meeting with Mr Abhisit she said she expressed concern about the safety of the many Myanmese activists in Thailand, fearing harassment from the military intelligence agents from both countries.

'Today wasn't a complete waste ... we feel the door is creaking open. We have to make sure it stays open for us. Today's meeting was still significant,' she said.

Myanmar is considered the worst rights abuser within the grouping, that also comprises Brunei, Cambodia, Indonesia, Laos, Malaysia, the Philippines, Singapore, Thailand and Vietnam.

Myanmar's secretive ruling military junta has jailed more than 3,000 political prisoners and has kept opposition democracy leader Aung San Suu Kyi under strict house arrest for six years. She has been under house arrest for most of the past 18 years.

Senior Thai diplomat Sihasak Phuangketkeow earlier defended plans for the body, saying it was important for it to 'evolve' in a diverse Asean committed to non-interference. 'We have to start somewhere,' he said when asked about the lack of any enforcement mechanism.

'You can condemn all you want but you can't make a difference on the ground,' said Mr Sihasak, who headed a meeting of senior Asean officials advising the leaders.

'The best way to prevent human rights abuses long term is to build a culture of respect for human rights ... [the body] is not a panacea but it will bring comfort to the people.'

The body was a key part of a charter signed in December in a bid to boost Asean's relevance and credibility after decades of the grouping being written off as a talk-shop that produces little action. It is expected to be finalised over the next year.

It will seek to promote international human rights norms and fund rights' education and dialogue.